Medieval people believed with great seriousness that final happiness lay on the other side of death. They did not expect it in its fullness on this earth. But the methods of modern science provide no grounds for belief that there is anything beyond death. Hence, the whole freight of human happiness has to be carried in the few short and uncertain years that are allowed to us before death ends it all. The quest for happiness becomes that much more hectic, more fraught with anxiety than it was to the people of the Middle Ages.
There is a further implication of the emergence of the concept of human rights.... [T]he concept would have been meaningless in an earlier age. "Rights" only exist where there is a legal and social structure that defines them. Anyone can, of course, assert a need or express a wish apart from such a legal or social structure. But a claim to a right must rest upon some juridical basis. Asserting a right where there is no such basis would be like writing a check on a nonexistent bank. Therefore, if the right of every person to life, liberty, and the pursuit of happiness is asserted, one has to ask, "Who is under obligation to honor the claim?" In the Middle Ages the answer was found within the network of reciprocal rights and duties. The man farming the land had a duty to provide troops to fight his lord's battle and a corresponding right to his lord's protection. Duties and rights were reciprocal. One could not exist without the other, and all were finite. But the quest for happiness is infinite. Who, then, has the infinite duty to honor the infinite claims of every person to the pursuit of happiness? The answer of the eighteenth century, and of those who have followed, is familiar: it is the nation-state. The nation-state replaces the holy church and the holy empire as the centerpiece in the post-Enlightenment ordering of society. Upon it devolves the duty of providing the means for life, liberty, and the pursuit of happiness. And since the pursuit of happiness is endless, the demands upon the state are without limit. If—for modern Western peoples—nature has taken the place of God as the ultimate reality with which we have to deal, the nation-state has taken the place of God as the source to which we look for happiness, health, and welfare.
Lesslie Newbigin, Foolishness to the Greeks: The Gospel and Western Culture (Grand Rapids, MI: Eerdmans, 1986), 26–7.